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Jim Coash

The genesis of speakers, Bob Carver's impact by Jim

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Greetings:  Of all the audio technologies, the genesis of loudspeakers is probably the most interesting and controversial.  When the interest in owning a music system for the home was at its peak, numerous entrepreneurs wanted to become involved both for fun and profit.  Some took the path that led to amp design, others had ideas for turntables and others turned to loudspeakers.  Many were in it for the money entirely and they simply hired engineers to come up with the next big thing. There were some who were really and truly a genius.  Speakers were occasionally viewed as the "easy" path to wealth. Plywood was invented during the war for boats and other things because metal was in short supply.  The war also drove driver technology.  Electro-Voice came up with workable speakers for many uses including in submarines.  They could  survive even under water.20140225060757819.jpg The ad you see was typical of what The Sound Room produced and ran in the Kalamazoo Gazette.  The ad department in the store would ask anyone who worked there if they would participate by having their picture taken.  Some did, others said they would look "stupid" and refused.  I volunteered and as a result I was in several.  Other salesmen told me I looked stupid but people did come in and recognize me.  If I did, so be it.  I was number one in sales most of the time.  This ad was pretty typical but if you saw the other ad I posted you know that some were dedicated to one system.  Here I am promoting JVC speakers.  In my last post about the Sorority system I used a pair of the large JVC speakers for their party room and they worked well.
 
Early speakers were nothing at all like we see today.  Not only were the materials available very limited, the technology was in its infancy.  I have a very old speaker that was made in the 1930s.  It is a round, carved, wooden box with a single "full range" electro-dynamic, full range driver inside.  It was made in Michigan and designed to be used with any kind of tube amplifier.  It did not work when I got it but it is interesting to look at.  Then, the output transformer was mounted on the frame of the speaker which, along with the fact that the magnets were not permanent but required power, which is why it is called electro-dynamic.  That meant you needed to connect a DC source, often a battery, to terminals that supplied power for the electromagnet that produced the magnetic field for the voice coil and connect signal wires as well. You will see the same thing in a lot of old radios from the early days. When the transformer moved to the chassis of the amp, someone decided that the "standard" impedance of speakers would be 8 ohms and amplifiers were built with a common terminal and a choice of "taps" usually labeled 2,4,8,16 & sometimes 32 ohms so that multiple speakers could be matched.  A single speaker used the 8 ohm taps, two in series used 16 and two in parallel used the 4.  Voice coils were difficult to make by hand so tolerances were loose.  Bobbins (with the wire wrapped around them) were paper as were cones.  For spiders and surrounds, treated cloth.
 
The baskets were usually stamped steel or an alloy and the magnets, iron.  The most common sizes were 8", 10" and 12". There were no separate drivers for highs or mids for a long time, hence, no crossover was needed.  Most companies added a paper, cone shaped piece to the dust cover over the coil and gap.  This was advertised as a "whizzer" cone to enhance high frequency response.  There was little data to support that.  This was the beginning of advertising things like the size and number of the speakers inside the box.  It was a clearly salable concept to say that your radio was better because it had larger speakers or more of them, again with no way to actually prove that.  People did listen but were highly subjectable to whatever the salesman said about his product.  By the late 40s and early 50s people like Leo Fender were searching for speakers suitable for instrument amps that were growing in size due to demand.  Early tube amps for instruments were the same design as those used in hi-fi products and musicians wanted more.  Leo responded with 30 and 40 watt amps and he needed larger speakers and better performance.  There was a divergence going on.  No one knew what a guitar was supposed to sound like so levels of distortion higher than those in home hi-fi were not a problem.  Amps could be made cheaper if the parts weren't as expensive and that somewhat "muddy" sound was an asset in some cases.  Not so in the hi-fi business.  People DID know what real instruments sounded like, especially the human voice.  If your system produced legible vocals, you would sell more.
 
Leo got a big boost when Jensen and a few others discovered Alnico for magnet structures.  The Ni (nickel) and Co (cobalt) added to the mix of metals made the magnets permanent, powerful and better able to handle closer tolerances than ever before.  Those speakers revolutionized sound quality and of course the hi-fi companies wanted that too.  Altec (engineer, James B. Lansing), and then we he opened his own company, JBL, Electro-Voice (Lou Burroughs and Al Kahn) joined Jensen and several others in the USA in taking on the task of building better speakers.  In Europe and England the same phenomena was happening.  Peter Walker (Quad), Raymond Cooke (KEF), Harry Olson (Linn), Irving Fried (IMF) and others were pushing the limits.  These men joined Americans Paul Klipsch (Klipschorn), Dr. Amar Bose (Bose 901), Edgar Villchur (Acoustic Research) Jon Dahlquist (Rectilinear) Avery Fisher (Fisher), Henry Kloss (A/R, Advent, Cambridge, Tivoli) and others began figuring out that there was much more involved in building speakers than had been previously thought.
 
Any one could contract with a furniture company to make relatively consistent boxes that were nice looking in a living room. Any one could order driver elements from companies all over the world.  But few people had considered just what made one speaker sound pretty good and another a dismal failure.  Now specialized driver elements were becoming available.  Smaller cones, smaller voice coils, finer wire, metal alloys, horn drivers and the horns themselves all needed careful engineering and another real problem was making sure the individual drivers worked in harmony.  That meant developing crossovers.  In various places around the world these developments took place in relative secrecy.  Each company knew that a breakthrough in technology could mean money.  A LOT of money.  Now a knew diversity was beginning.  Each of the engineers worked on the same problem but the often used different approaches and their solutions varied wildly.  In the early 60s there were a group of companies in California (Altec, JBL, Infinity,etc.) and another on the east coast (Acoustic Research, Bose, Advent, KLH, etc.).  Hence the "California Sound (ported boxes, high efficiency, bumped up bass, large multiple driver systems) and the East Coast or Cambridge sound (infinite baffle, sealed enclosures, bookshelf speakers, fewer drivers)  One major division between them was efficiency.  The Cambridge sound was usually considered superior by audiophiles but the speakers needed more power.  Much more power.
 
Not to be left out, in the Midwest we had Klipsch (corner horn), Jim Winey (Magnaplanar), Electro-Voice (blending pro sound with home quality) and a few others who came along eventually.  McIntosh developed speakers under Gordon Gow, Jim Thiel and his compatriot Mr. Small developed a very complex set of equations and formulas (Thiele/Small Speaker parameters) that finally explained many of the complexities of the interaction of speaker parts, their specifications, the enclosures and the room environment.  It was ground breaking.  Other companies had their own "math" but this was really the first truly comprehensive analysis done and it applied in every application.  No matter what you used or where you used it, home, auditorium, automobile or out of doors, you could accurately predict how variables could be manipulated to improve both sound and reliability.  The early Thiel speakers were "time aligned" placing the drivers in the same plane from the listening perspective.  Others had done this including Jon Dahlquist in the DQ-10.  But, once again, although planar alignment clearly had advantages, others said that co-axial which aligned the drivers in both vertical and horizontal planes were better.
 
This brings us to the point where the true audiophiles began to pick out certain speaker designs as "inherently superior".  Just what were they?  They were those designs that were able to somehow combine all of the best technologies into a single package.  If you look at those speakers they are all attempts to do just that.  On the all time lists of the best speakers you usually find these and others of similar concept.  Quad Electrostatic, Linn Isobarik, Infinity IRS, Dahlquist DQ-10, WAMM (Wilson Audio Monitor), Maneplanar Tympani, JBL 250 Ti, Yamaha NS-1000, KLH Model 9, KEF 107, Martin/Logan CLS, Thiel CS 3.6 and a few others.  Where does this lead?  It leads to Bob Carver.
 
Bob talks in his description of his latest speaker about his influences and the men who built the above speakers are on that list. They knew, as Bob knows that no box does anything good for a speaker.  Those men weer trying to build something that they could not because neither the materials nor the understanding existed to solve the problems they were well aware existed. Every one of them was forced to make compromises that they did not wish to.  I am not saying the Bob was the first to understand them or that his current speakers have solved them all but starting with his first "Amazing Loudspeaker" he has been on the right track.  After 20 years of dedication and tedious research he has produced a product that really does solve more of the problems in speaker design than anything I have ever seen.  Do I wish I could own a pair?  Of course, but not only are they completely out of my reach financially, I would have a difficult time finding a way to implement them into my home and still have a happy wife.  (Happy Wife, Happy Life) For those of you who can both afford and use Bob's latest creation, I encourage you to explore.  Now remember that I have never seen or heard this new model.  But I have owned and/or listened to virtually every speaker I listed above.  Some at a CES show, some on the showroom floor at The Sound Room and/or Stereo Showcase.
 
I have in other forums listed most of the speakers I have owned but here is, to the best of my recollection, a list of speakers I owned and used in my own system.  A few I only used in my mobile system.  First speakers, my Dad's Electro-Voice 15TRX in Heath enclosures, then, roughly in order,  KLH Model 11, JBL D-130 (custom cabinets), Heath/JBL, Large Advents, Double Advents, Triple Advents, Electro-Voice Interface: A, Double Interface: A, Bose 901 IV (mobile only), Electro-Voice S-1503 (mobile only), Dahlquist DQ-10, Yamaha NS-1000, Genesis 44, Yamaha MS-500, Paradigm Mini-Monitor/PS-10 sub, Linn Isobarik, KEF 102, KEF 103, KEF 104, KEF 104.2, KEF Reference Two, McIntosh ML-10c, KEF Reference One/Sunfire Signature Sub (currently), Electro-Voice SX-200 system with Sb-200 subs (mobile only), Electro-Voice Aries Modified (party barn only) and a few others I am sure I missed.  You can add to this list those that I heard only in my store, Infinity IRS and other models, Quad ESL, Spendor, Rogers LS35A, many KEF models, many A/R models, Thiels, Martin/Logan, NHT, Paradigm, PSB, Sonus Faber, McIntosh, Boston Acoustics and plenty of other nondescript models from all the product lines I represented over nearly 40 years.  Finally, many, many speakers at more than a dozen CES shows between 1978 and 1997.  Plus those heard in homes and stores I visited and cannot accurately recall.
 
That is a big list.  There is one company I left off.  Bob Carver came to our store several times and discussed his products with my staff and I.  He made excellent demonstrations and answered all of our questions.  From his first Amazing Loudspeakers in the mid Eighties to the last model I heard in 2001, March, the day Stereo Showcase closed it's doors for good.  I never heard anything I thought was better.  My wife told me several times, they are fantastic, but they will not work in our room.  The closest I came was when Bob came out with the ALS-III.  She almost went for those.  The best alternative I have ever found that she really likes are the KEF Reference.  They are very good.  If you want to know more about them look them up on-line.  They use a "Coupled-Cavity" bass design and "Uni-Q" technology on the High/Mid driver.  Very good imaging, very stable, good bass but nicely enhanced by the Sunfire Sub.  They fit nicely and are discreet.  You know I have at least a dozen pairs of speakers in other parts of the house, most are KEF.  We listen every day.  Questions?  Jim
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wow another great read by Jim. eusa_clap.gif You are right , the complexities of speaker building and all the math formulas are most overwhelming by the majority of DIY'ers  Matching appropriate drivers to appropriate enclousres with appropriate porting (or non porting) and appropriate x-overs can exhaust the mind before you even get started, and many wind up with an attempt  with dismal outcomes.  Really enjoyed the history of the many manufactures you listed.  One that was omitted was Warfedale designed by Gilber Briggs.  Would enjoy your prospectives on his works and designs.
 
Dano
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Do not over complicate the process of fun. It is really easy once you wrap your head around it. Easier than not anyway for myself. You do not always need the most elaborite design to have fun i swear. Building and designing speakers is a hoot.

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Once again, thank you for taking the time to post this history, Jim! eusa_clap.gif
 
What can you tell us about your customers who bought Carver speakers? What amps did they drive them with? What did they think of the sound? Did they ever trade them back for something different?  
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What can you tell us about your customers who bought Carver speakers? What amps did they drive them with? What did they think of the sound? Did they ever trade them back for something different?  

Yup...I'm curious too.
 
 
 
 
A minor (VERY minor) quibble is that you describe Theile/Small mathematics and then discuss Thiel brand loudspeakers.  Theile and Thiel might be easily confused, but the math guys (Theile and Small) were Australian, while Thiel loudspeakers are American--Lexington KY.
 
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Another name is the work of Winslow Burhoe, engineer at AR, KLH, Epi, Burhoe Acoustics, Boston Acoustics, Energy, Nuance, and others, starting back in the 60s.
 
I have every one of the original Epi designs, except for the M601s and the rare M1000's (around a 1000 pairs were manufactured total from 73 to 78).
Looking for a pair of those to rebuild someday. There is a spot reserved next to my AL III+'s for them.   
 
Diggin' these historical threads, Jim. Keep them coming. 
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